Gen 4 to Gen 3
Thread Starter
Teching In
Joined: Jul 2010
Posts: 23
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Gen 4 to Gen 3 Hi. I have a 07 Sierra with a blown up gen 4 5.3
I also have a gen 3 lq9 sitting in my garage. I'm sure you can see where this is going. I'm aware of the reluctor wheel differences, but can that be fixed with a lq9 tune on the Gen 4 ecu? I'm sure I'll have to modify the harness too. Any help is appreciated.
I also have a gen 3 lq9 sitting in my garage. I'm sure you can see where this is going. I'm aware of the reluctor wheel differences, but can that be fixed with a lq9 tune on the Gen 4 ecu? I'm sure I'll have to modify the harness too. Any help is appreciated.
Last edited by SlowAndHighTBI; Mar 1, 2019 at 02:58 PM.
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,616
From: Central Cal.
Reluctors and ECU's can't be mixed and matched. Gen IV ECU MUST use a 58 tooth reluctor, and a Gen III ECU MUST use 24 tooth.
The ECU's use totally different operating systems. They are different as night and day.
The ECU's use totally different operating systems. They are different as night and day.
TECH Regular
Joined: Sep 2007
Posts: 443
Likes: 3
From: Kansas City, MO
Since you'll have the LQ9 out, just take the crankshaft to a machine shop and have them press on a 58x reluctor. Then just get a 4x cam gear from an LS2 and front cover/cam sensor to match. Buy a cam and knock sensor conversion harness and you're in business.
